Reversing counting chain



Feb. 5, 1963 G. l.. HINKLE r-:TAL

REVERSING COUNTING CHAIN Filed April 26. 1960 4 3 Sheets-Sheet 1 Ew NE ....2522 umu on INVENTORS GLENBER l.. HINKLE L'EMUEL R. BRE ESE Feb- 5, 1963 G. L.. HINKLE rs1-AL 3,076,918

REvERsING couNTING CHAIN Feb. 5, 1963 G. L. HINKLE ETAL REVERSING coUNTING CHAIN 3 Sheets-Sheet 3 Filed April 26. 1960 U f5 on. E A www w lllrllll 1 E; n n (E on. o.:

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INVENTORS GLENBER L. HINKLE LEMUEL R. BREESEI BY ,wdw /Mffwm S'di REWESHNG JNTING CHAEN Gienaer L Hinide and Lemuef E. Bresse, Galion, iiio, assignors to North Eectric Company, Gaiion, Ohio, a coreration of @hin Fiied Apr. 26, 1Mb, Lder. No. 24,792 1G Ciairns. (Ci. Sli-31630) This invention is directed to a counting chain circuit and more particularly to such a circuit which is effective to register the receipt of successive impulses for adding to or subtracting from the count, with a simple and economical circuit arrangement having a minimum number of components.

The term counting chain, general to an electrical circuit count-indicating relays, and ass to such count-indicating relays o receipt of successive electrical count relays to continually provide the total count for the received impulses. Reversing counting chains have been produced to operate either in the forward or reverse direction and thus successively add or subtract the received impulses from the previous total, but such circuits have generally been complex and expensive. It is therefore a primary object of the present invention to provide a reversing counting chain which requires a minimum amount of equipment and is simple both in construction and operation.

It is another object of the invention to provide an instantly reversible counting chain, i.e., a chain which operates either in the forward or reverse direction (to either add or subtract) with respect to each succeeding received impulse and which further is operative in an endless ring.

sent invention is to provide circuit with preset means, mber can be preset thereon in response to received imtract digits from the preset as used herein, refers in comprising a number of ociated circuitry coupled perable in response to the impulses to energize the before the chain is operated pulses to either add or sub number.

seciuence relay. Each block includes a series circuit comprising a first and a second contact set controlled by the sequence relay, the winding of the count relay, a set of make contacts carried by the count relay, and the winding of its associated sequence relay which is coupled between supply conductors across which a potential difference is applied. The sequence relay carries, in addition to its first and second contact sets, at least two sets of make contacts, the first set being connected between the line over which forward or additive impulses are applied and the winding of the next higher count relay. Thus, receipt of a forward or additive impulse after operation of the sequence relay in a given block will effect operation of the count relay in the next higher block. The second set of make contacts carried by the sequence relay in the given block is coupled between the conductor over which reverse or subtractive impulses are received and the winding of the count relay in the next lower block of the chain. Thus, responsive to receipt of a reverse or subtractive impulse after operation of the sequence relay in the given block, the count relay in the next lower block will be operated. Such operation lends great versatility to the system, permitting reverse action of the chain even with respect to successive impulses.

Another feature of the invention is the inclusion of preset means, the use of which is effective to operate the respective count relay and its associated sequence relay in reiterated Feb, 5, E963 2 any one of the blocks in the counting chain prior to receipt of any impulses. In this manner the received impulses may be either added to or subtracted from the number which was preset on the counting chain.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The invention itself, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings, in the several figures of which like reference numerals identify like elements, and in which:

FIGURE 1 is a schematic diagram depicting a preferred embodiment of the inventive counting chain circuit; and

FIGURE 2 is a partial schematic diagram, useful in understanding the interconnection of a plurality of counting chain banks of the type depicted in FIGURE l.

The counting chain bank or decade circuit depicted in FIGURE 1 is operable to add or subtract received impulses, the circuit being operable in a continuous ring fashion, so that as the count exceeds nine, the Zero count relay is reoperated, and as the count reaches 25, the chain would have been operated through two and one-half cornplete revolutions, leaving the count relay indicating digit 5 operated after receipt of the impulse which results in a total count of 25. Each digit from 0 to 9, inclusive, is indicated by operation of one of count relays l-Q, respectively, and as will be made apparent by the subsequent explanation, each of count relays iti-i9 effects the operation of an associated one of the sequence relays Zit-29. Operation of a given sequence relay prepares both the next higher and next lower count relays for operation prior to receipt of the next impulse, and which count relay of the prepared pair is subsequently operated is determined by the nature of the next received impulse, i.e., additive or subtractive.

CRCUIT OF FGURE l-UNiTS BANK The counting chain bank of FlG-URE l has a pair of input terminals 31 and 32; these terminals are indicated as being of positive and negative polarity only to signify that a potential difference is applied over these terminals to energize the components of the counting chain. The polarity of the energizing voltage may be reversed without affecting the operation or components of the counting chain.

A normally-closed reset switch 33 is connected between input terminal 3l and supply conductor 3d. Each of the counting chain blocks (3 9, which will be more explicitly defined hereinafter, is coupled between supply conductors 34 and 35, either directly or over intermediate conductors.

The forward or add actuating circuit coupled between supply conductors 34 and 35 includes a forward switch 39, the winding of forward relay di), and break contacts 50a of reverse relay Si). In the drawings a relay winding is depicted by a circle enclosing the reference numeral which designates the relay. The contacts of each relay are not shown adjacent thereto, but are referenced by the same numeral which designates the relay and are specifically identified by a letter suiiix. Moreover, make contacts are indicated by an X at the junction of the conductors which are connected by closure of such contacts, and break contacts are indicated by a drawn perpendicular to the conductors which are connected over the break contacts. This type of representation, including the contacts detached from the relay winding and the symbols for the make and break contacts, are now well known and understood and are explained in detail in the Bell Laboratories Record of July, 1954, pages auras; e

3 261-266, and in Communications and Electronics, Sep-V tember, 1955, pages 505-513.

Coupled in parallel with the forward or additive actuating circuit is the reverse or subtractive actuating circuit comprising reverse switch 49, the winding of reverse relay 5), and break contacts 49a of forward relay 40. As will be set out more fully hereinafter, each closure of forwardswitch 39 is effective to advance thecounting chain one step by eiecting operation of the next higher count relay and releasing the count relay which was operated prior to closure of forward switch 39. In like manner, closure of reverse switch 49 is eiiective to yrelease the count relay which was operated prior to closure of the reverse switch and to operate the next lower count relay.

A normally open preset switch 33 is connected between supply conductor 34 and preset conductor 36; when switch 33 is closed, a path is completed thereover so that the potential appearing on supply conductor 34 also appears on preset conductor36. A slider 37 is connected so that one terminal thereof always contacts preset conductor 36, and slider 37 is displaceable along conductor 36 so that the other terminal thereof may contact one of the preset input terminals 697-69 of the, counting` chain blocks @-9, each terminal 66469 being connected to a different one of the blocks. It will be apparent to those skilled in the` art that conductor 36 may bejthe central connection of a rotary wafer switch, and slider 37 may be the displaceable contact of such wafer switch. The manner in which displacement of slider 37 is effective to cause the counting chain to commence operationA from any` preassigned numberwill be explained hereinafter.

AA set of make contactsk 40d of forward relay 40; is,

coupled between supply conductor 34 and forwardY (or add) conductor 42. Thus, when relay 40 is operated, contacts 40d are closed and the potential appearing at input terminal 31 and supply conductor 34 is coupled over con-A tacts 40d to forward conductor 42. In like manner, make contacts 50d of reverse relay Stiare coupled between supply conductor 34 and reverse (or subtract) conductor 43, so that operation of reverse relay 50 is effective to close contacts 50d and' place reverse conductor 43 at the same potential as that of input terminal 31A and supply conductor 34.

Connected in series between supply conductor 35 and a iirst hold conductor 45 rare two sets of break contacts, Mib and 5012. Thus, when both the forward and the reverse relay are released, rst hold lconductor 45is at the potential of supply conductor 35 and input terminal 32; this circuit is interrupted by' operation of either forward relay 40er reverse relay 50. A second hold conductor 46 is connected over a resistor 47 to one side of parallelconnected make contact sets 40C and 50c, and from thel other side of these contact sets over supplyconductor 35 to terminal 32. Accordingly operation of either relay 4) or 50 is effective to complete the circuit from conductor 45 over the operated one' of the contact sets, 40e or 50c to supply conductor 35 and terminal 32.v

As explained generally hereinbefore, each counting chain block includes both a count relay and an associatedY sequence relay. The circuitry of the rst block, in which the count relay is operated to indicate digit 0, will now be described.

The rst counting chain block comprises a count relay it) and itsV associated sequence relay 2,0. Count relay includes a set of make .contacts 10a, and sequence relay 26l includes a slet of'break'con'tacts 20a and four Vsets of make contacts, Zibb, c, 25d and 20e. Those skilled in the lart will recognize that each count relay may include one`or more additional contact sets which may be connected to external equipment, such as indicating lights, control circuitsin a computer,` or other ,structure for g use of the particular-count indicatedin I(the 'sysuchjssociated circuitry, however,

is not pertinent toA the inventive concept and has therefore been omitted from the drawings.

The lower terminal of the winding of count relay 10 is connected over break contacts Zta to supply conductor 35, and over make contacts Zilb to first hold conductor 45. The upper terminal of the winding of count relay 10 is coupled over make contacts 10a and the winding of its associated sequence relay 20 to supply conductor 34. From the series connection of the windings of relays 10 and 20, with make contacts lila therebetween, it is evi-v dent that operation of count relay it) will close its makecontacts 10a and eirect energization of its associated sequence relay 20 over a circuit including the winding.

of the count relay.

Make contacts 20c of sequence relayl 2Q are connected between forward drive conductor 42 and the winding of next higher count relay 11; operation of sequence relay` 20` is thus effective to close contacts Ziic and prepare an operating circuit for count relay 11, which circuit canv the reverse (or subtract) circuit. Sequence relay Zi)v also includes holding contacts 29e connected between the lower terminal of its winding and second hold conduc-` tor 46. Each of the other blocks of the chain is constructed and connected in like manner. The operation of.

the4 counting chain in response to receipt .of a single impulse and specifically a forwardv or additive impulse, willnow be described.

' Prior to receipt of any impulse to eftectoperationof the counting chain, reset switch 33 must .bek momentarily' opened to clear any count then standingin the counting: chain (unless, of course, it is desired to add or subtractv from such standing` count as the system commences op.; eration). Slider 37 must then be positioned to engage'A one of preset contacts 63-69 and preset switch 38 must be momentarily closed. This procedure is necessary to` operate fone ofthe count relays and its associated sequence relay, which sequence relay prepares operating. circuits for both the next higher and next lower Icount relays. For purposesof this initial explanation, it is assumedrth'at a count other than 0 is registered on the4 chain and it is desired to start from 0, and to tally or register each received impulseby adding it to the starting number (G). Accordingly reset switch 33 is opened and reclosed to ensure. thatall relaysare de-energized, and slider 37 is positionedy as shown, betweeny preset conductor 35 and presetl'terminal 6i) of the first or 0) block. Closure of preset switchv38 completes an operating cir-I cuit for count relay lil, which circuit extends from posi, tive battery over input terminal 31, 4reset switch 33, supply conductor 34,` presetswitch 33, preset conductor 36, slider 37,y preset terminal 6i) of thev zero block, the winding of relay liti, break contacts 26a, supply conductor 35,I

and'input terminal 32 to negative 'bz-ittery.- Count relay liipoperates, and at its contacts 10a completes an operating circuit for its' associated` sequence refay 20, which circuit extends froml positivebattery over input terminal 31, reset switch 33, supply conductor 34, the winding of relay 2t), makev contacts lita, the winding of relay 1i),l break contacts 20a, supply conductor 35, and finputterrni` nal l32 fto negative battery. Sequence' relayZti operates, and at its contacts Zttainterrupts the above-described op-A erating circuits for Arelays 10 and 2d; at its; contactsl 20h completes a holding circuit over iir'stf hold conductor 45 for relaysv it) and Zit, so that these relays arenot released,F but are transferred from `a lcircuit'includingv con-` tacts 20a to' a circuit including contacts Zibb; at its conf4 tacts 20c prepates' an operating circuity for 'next higherv i have the subsequentoperations commence from that numerical-value. Accordingly operation in both the forward and reverse directions will now be described, commencing with the value 4 preset on the counting chain by movement of slider 37 to engage preset contact o4 of block 4.

if a count was previously registered in the counting chain, reset switch 33 is momentarily opened to dre-energize the circuit, thereby effecting the release of the operated counting and sequence relays, and is thereafter reclosed to provide power from input terminal 3i to conductor 34 and to one side of preset switc 3S.

To effect presetting of the counting chain, slider 37 is displaced to the right as shown in the drawings until it effects a conductive contact between present conductor 3o and preset terminal o4 of block 4, which block cornprises count and sequence relays 14 and 24 `and their Iassociated circuitry.

After displacing slider 37 to engage contact 64, preset switch T13 is-depressed and an operating circuit for count relay 14 is completed, which circuit extends from positive battery over input terminal 3l, reset switch 33, supply conductor 34, preset switch 3S, preset conductor 36, slider 37, terminal dfi, the winding of count relay f4, break contacts 24a, conductor 3S, and input terminal 32 to negative battery. Count relay lil operates, and at its contacts 14a completes an operating circuit for its associated sequence relay 2,4, which circuit extends from positive battery over input terminal 3l, reset switch 33, supply conductor 34, the winding off sequence relay 24, contacts 14a, the winding of count relay f4, contacts 24a, and supply conductor 35 to input terminal 32. Sequence relay 24 operates, and at its contacts 24a interrupts the operating circuit for relays 24 and 14 in block 4 and at its contacts 24h completes a holding circuit for these relays which extends over contacts 24h, first hold conductor 45, contacts Stlb, adb, supply conductor 35, and input terminal 32 to negative battery; at its contacts 24C prepares an operating circuit for next higher count relay l5; at its contacts 24d prepares an operating circuit yfor next lower count relay i3; and at its contacts 24e prepares a self-holding circuit which at this time is interrupted at contacts luc and Stic.

To illustrate the versatility of the counting chain and its ability to operate in either the forward or reverse direction as each successive impulse is received, receipt of three consecutive impulses, a forward impulse, a reverse impulse and then another forward impulse, will now be described. As forward switch 39 is closed to energize forward relay 40, relay litt operates and at its contacts fitta interrupts the operating circuit for relay Ell to preclude operation of the reverse relay at this time; at its contacts dbb interrupts ythe holding circuit for relays l@ and 24 in block d, and at its contacts 40C completes a holding circuit for sequence relay 2dso that only count relay 14 isreleased; and at its contacts Mld completes a previously prepared energizing circuit for next higher count relay 15, which circuit extends from positive battery over input terminal 3l, reset switch 33, supply conductor 3d, contacts litio', forward drive conductor 42, contacts 24C, the winding of count relay l5, contacts 25a, supply conductor 35, and input terminal 31E to negative battery.

Count relay l5 operates and closes its associated make contacts llSa, thus completing an energizing circuit for its associated sequence relay 25 which extends from positive battery over input terminal 3l, reset switch 33, supply conductor 34, the winding of sequence relay Z5, contacts 15a, the winding of count relay f5, break contacts 25a, supply conductor 35, and input terminal 32 to negative battery. Sequence relay operates, and at its contacts 25a interrupts the operating circuit and at its contacts 255 completes a holding circuit for count and sequence relays l5 and 25; at its contacts 25C prepares an operating circuit for nexthighercount relay 16; vas its contacts 25d prepares an operatingcircuit for next lower count relay 14;,

and at its contacts ZSeprepares a self-holding circuit.

By this time forward relay fatt has released, and at its; contacts elle interrupted the holding circuit for sequencev relay 2d, which releases.

At this stage ofthe operating sequence, the equipment having been preset to commence operation at numeral 4. (count relay i4 and its associated sequence relay 2d oper-- 5t? operates and at its contacts :fld completes an operating.

circuit for next lower count relay i4 which extends from positive battery over input terminal 31, reset switchy 33, supply conductor 34, contacts ddd, reverse drive con.- ductor d3, contacts 25a', the winding of count relay 14, contacts conductor 35, and input terminal 32 to nega-V tive battery. Operation of reverse relay-59 at its contacts Sub interrupts the holding circuit for count relay `i5, whichreleases. Count relay i4 operates, and at its contacts 14a completes a previously-described operating circuit forits associated sequence relay 24. Thus sequence relay 24 operates and prepares operating circuits for both next higher count relay 15 and next lower count relay 13. Reverse relay Sureleases after supplying the reverse impulse an-d at its contacts 5th: interrupts the holding circuit for sequence relay 2S, which releases. Accordingly at this time Yonly relayslland 2d in block 4 are operated, and operating circuits have been prepared for each of the next higher and lower count relays in a manner described hereinbefore.

Thus, having commenced operation with the equipment indicating numeral 4 by operation of count relay 14, and having added an impulse and subtracted an impulse, the counting chain indicates no net change because count relay 14 is now operated.

Another actuation of forward switch 39 to operate forward relay 4t) will cause the operation of relays 15 and 2S in block 5, and the release of relays ld and 2d in block 4, in a manner previously described in detail. Accordingly count relay l5 and its associated sequence relay Z5 will be operated after the receipt of three consecutive impulses, two of which are add or forward impulses and the third of which is a reverse or subtractive impulse. Thus it is evident` that the counting chain is operable. to instantly reverse its operation from one to another direction, and will provide a net tally of the total number of impulses supplied thereto, no matter the sense (forward or reverse) of each of those impulses.

Reset switch 33 is provided to reset the'equi'pment by returning all of the count and sequence relays therein to the released condition responsive to actuation of the switch. Opening of reset switch 33 interrupts the con.- nection between positive battery at input terminal 3l and supply conductor 3d, thereby removing the energizing potential which is requisite to operate not only the forward and reverse relays 4o and 5d, but each of the count and sequence relays in the individual bloclts of the counting chain itself. After reclosure of the reset switch, the er1- ergizing potential is again supplied from positive battery over input terminal 3l to supply conductor 34, and the equipment is conditioned for operation.

CIRCUT OF FGURE Z-TENS BANK Those skilled in the art will recognize that a plurality of banks or decades of the type shown in FIGURE l can be coupled together to register a larger total than is possible with the single there shown. For example, the connection of another similar bank of counting chain blocks to register the tens digit would permit counting 9 from O to $9, rather than from to 9 as is possible with the single bank of FIGURE 1.

The second counting chain bank or decade which may be added to the tirst to provide for counting from 0 to 99 is the same as the bank depicted in FlGUll 1, except that each of the forward and reverse switches has been replaced by two contact sets. Each of these four added contact sets, designated llb, Edf, b, and Edf in FIGURE 2., is actuated by a corresponding one or" count relays l@ and r9 and their associated sequence relays Ztl and 29.

As shown in FIGURE 2, the operating circuit for forward relay lltl of the tens bank extends from positive battery over input terminal l3l, rese switch i331, make contacts ld!) of lirst count relay lll in the units bank (FlGUiE l), make contacts 2W of last sequence relay 29 in the units bank, the winding of forward relay Tied, break contacts ila, supply conductor 135, and input terminal i3?. to negative battery. Accordingly operation of count relay l@ in the units bank effects operation of its associated sequence relay 29, as explained above. Sequence relay 29 operates and at its contacts 29f (FIC- URE 2) prepares an operating circuit for forward relay All. After receipt of the next forward impulse in the units bank, count relay il@ operates and at its contacts lill; completes the operating circuit for forward relay Till@ in the tens banl'. Operation of relay ldll steps the tens bank to indicate the next higher digit in a manner obvious from the detailed showing and explanation of the units bank. It is therefore manifest that for each ten forward impulses received by the units bank, relay Mil of the tens bank is operated once.

ln similar fashion, the operating circuit for reverse relay l5@ of the tens bank extends from positive battery over input terminal l3l, reset switch ll, contacts i9!) of last count relay i9 in the units bank, contacts Ztlf of first sequence relay Ztl in the units bank, the winding of relay lill), contacts ldiltz, conductor i3d and input terminal "-32 to negative battery, rlhus it is evident that a reverse or subtract impulse is transmitted to the tens bank responsive to concomitant operation of iirst sequence relay 2d and last count relay l@ in the units bank. That is, after count relay lo and its associated sequence relay 2li are operated in block il of the units bank to indicate numeral (i, contacts Zllf of sequence relay 2d are closed to prepare an operating circuit for reverse relay .ld in tbe tens bank. Responsive to receipt or" the next reverse impulse in the units bank, count relay i9 is operated over contacts ddd and Ztld, thus completing an operating circuit for count relay i9 which operates and at its contacts 1% completes the operating circuit for reverse relay lilo in the tens bank. Accordinaly the indication on the tens bank is stepped backward or driven in reverse by one digit, at the same time that the indication in the units bank is stepped backward by one digit.

Suppose that, as an illustrative example, the tens bank is initially indicating numeral 7 and the units bank numeral O, or a total of 70. Responsive to subsequent receipt of a reverse impulse in the units bank, count relay lil is released and count relay i9 is operated, thus indicating numeral 9 as the units value, at the same time that the count is stepped in reverse through one digit in the tens bank, from 7 to 6, to indicate numeral 6 as the tens value. Accordingly the combined tens and units counting cbain banks now indicate numeral 69, after the subtraction of one digit from the previous total. Thus it is manifest that the connection of contacts l'b and 23j in series with reverse relay 15d in the tens bank is the ele .rical analogy of the mathematical operation of borrowing from the tens column in subtraction, when the units digit of the subtrahend is greater in magnitude than the units digit of the minuend. lt is clear that any number of separate counting chain banks or decades can be thus intercoupled, dependinx7 on the total to be registered or tallied.

Thus it is evident that the novel reversing counting chain of the invention does not necessitate the use of relays interconnected so there must be a long sequence of series make or break operations to advance the indication by a single digit. A single bank or decade of the counting chain can be connected to operate in an endless ring fashion, and if a plurality of such banks are connected together, the entire combination can readily be operated in an endless ring even as a single bank or decade of the equipment. The novel chain can easily be driven forward or backward, and its simplicity is evident when it is noted that the sequence relay associated with each count relay utilizes only two contact sets to prepare both the adjoining (next higher and next lower) count relays for operation. Likewise the count relays are of a less complex structure, each requiring only a single set of make contacts to energize its associated sequence relay. Accordingly a simple reversingr counting chain has been provided with a minimum of relays and associated circuitry.

Although only a particular embodiment of the invention has been shown and described, it is apparent that modifications and alterations may ybe made therein, and it is intended in the appended claims to cover all such modifications and alterations as may fall within the true spirit and scope of the invention.

yWhat is claimed is:

1. A counting chain comprising: a plurality of counting chain blocks, each of said blocks comprising input sans, a count relay operative responsive to receipt of an impulse over said input means, and au associated sequence relay connected for operation responsive to operation of its respective count relay; a lirst means operable by each of said sequence relays to prepare an operating circuit for the next higher count relay responsive to operation of a given one or said sequence relays; and a second means operable by each of said sequence relays to prepare an operating circuit for the next lower count relay responsive to operation of said given sequence relay.

2. A counting chain comprising: a plurality of counting chain blocks, each of said blocks comprising input means, a count relay operative responsive to receipt of an impulse over said input means, and an associated sequence relay connected for operation responsive to operation of its respective count relay; a lirst contact set operable by each of said sequence relays to prepare an operating circuit for the next higher count relay responsive to operation of a given one of said sequence relays; and a second Contact set operable by each of ssi-d sequence relays to prepare an operating circuit for the next lower count relay responsive to operation of said given sequence relay.

3. A counting chain including both forward and reverse drive conductors and further comprising: a plurality of counting chain blocks, each of said blocks comprising input means, a count relay including a winding and a contact set operative responsive to receiptl of an impulse over said input means, and an associated sequence relay having a winding seriescoupled with seid count relay Contact set and said count relay winding; a first contact set on eacll of said sequence relays coupled between said forward drive conductor and the winding of the next higher count relay to prepare an operating circuit for said next higher count relay responsive to operation of a given one of said sequence relays; and a second Contact set on each of said sequence relays coupled between said reverse drive conductor the winding of the next lower count relay to prepare on operating circuit for said next lower count relay responsive to operation of said given sequence relay.

4. A counting chain comprising: a forward drive conductor connected for the selective transmission of forward impulses thereover; a reverse drive conductor connected for the selective transmission or" reverse impulses thereover; a plurality of counting chain blocks, each of said locks comprising input means, a count relay including a lll.

winding and a contact set operative responsive to receipt of an impulse over said input means, and an associated sequence relay having a winding series-coupled with both the contact set and the winding ot its respective count relay to e'iiect operation of a given sequence relay responsive yto operation of its respective count relay; a iirst contact set on each of said sequence relays coupled between said forward drive conductor and the winding of the count relay in the next higher block to prepare an operating circuit for said next higher count relay responsive to operation of said given sequence relay; a second contact set oneach of said sequence relays coupled between said reverse drive conductor and the winding of the count, relay in the next lower block to prepare an operating circuit for said next lower count relay responsive to operation of said given sequence relay; and means for selectively applying an impulse over one of said drive conductors to one of said prepared operating circuits to operate an alternative one of said next higher and next lower` count relays.-

5. A counting chain comprising: a pair of supply con-` ductors; a forward drive conductor connected for selective coupling to one of said supply conductors to transmit forward impulses oversaid forwarddrive conductor; a reverse drive conductor connected for selective coupling-to said one supply conductor to transmit reverse impulses over said reverse drive conductor; means for applying a potential difference across said supply conductors; a plurality of counting chain blocks, each of said blocks cornprising input means, a count relay including a Winding and a contact set operative responsive to receipt of an impulse over said input means, and an associated sequence relay having a winding series-coupled with both the contact set and the winding of its respective count relay to elect operation of a given sequence relay responsive to operation of its respective count relay; a first contact set on each of said sequence relays coupled between said forward drive conductor and the winding of the count relay in the next higher block to prepare an operating circuit for said next higher count relay responsive to operation of said given sequence relay; a second contact set on each of said sequence relays coupled between said reverse drive conductor and the winding ofthe count relay in the next lower block to prepare an operating circuit for said next lower count relay responsive to operation of said given sequence relay; and means for selectively coupling said forward and reverse drive conductors to said one supply conductor to transmit an impulse to one of said prepared operating circuits to operate an alternative one of said next higher and next lower count relays.

6. A counting chain comprising: a plurality of counting chain blocks, each of said blocks comprising input means, a count relay operative responsive to receipt of an impulse over said input means, and an associated sequence relay connected for operation responsive to operation of its respective count relay; a iirst Contact set operable by each of said sequence relays to prepare an operating circuit for the next higher count relay responsive to operation of a given one of said sequence relays; a second contact set operable by each of said sequence relays to prepare an operating circuit for the next lower count relay responsive to operation o said given sequence relay; and means for presetting a desired number on the counting chain.

7. A counting chain comprising: a plurality of counting chain blocks, each of said blocks comprising input means, a count relay operative responsive to receipt of an impulse over said input means, and an associated sequence relay connected for operation responsive to operation of its respective c ount relay; a iirst contact set operable by each of said sequence relays to prepare an operating circuit for the next higher count relay responsive to operation of a given one or said sequence relays; a second contact set operable by each of said sequence relays to prepare an operatingcircuit for the next lower count relay responsive to operation of said given sequence relay', and preset means for selectively applying an impulse to a preselected one l2 of said count relays to operate said one count relay and thereby preset a desired number on the counting chain.

8. A counting chain com` rising: a pair ot supply conductors; a forward drive conductor connected for selective. coupling to one of said supply conductors to transmit forward impulses over said forward drive conductor; a reverse drive conductor connected for selective coupling to said one supply conductor to transmitreverse impulses over said reverse drive conductor; a preset conductor connectedfor selective coupling to said one supply conductor to transmit a preset impulse over said preset conductor; means for applyinga potential dilierence across said supply conductors; a plurality of counting chain blocks, each of said blocks comprising input means, a count relay including a winding and a contact set operative responsive to receipt of an impulse. over said input means, and an associated sequence relay having a winding series-coupled with both the 'contact set and the winding of its respective count relay to effect operation of a given sequence relay responsive to operation of Vits respective count relay; preset means for selectively coupling said preset conductor to the input means of a given one ,ofl said count relaysV to eiiect operation of said count relay and its associated given sequence relay to insert a preset number on the counting chain; a iirst contact set onsaid given sequence relay coupled between said forward drive conductor and .the winding of the count relay inthe next higher block to prepare an operating circuit for said next higher count relay responsive to operation of said given sequence relay; a second contact set on said given'sequeries relay coupled between said reverse drive conductor and the winding of the count relay in the next lower block to prepare an operating circuit for said next lower count relay responsive to operation of said given sequence relay; and means for selectively coupling saidforward and reverse drive conductors to said one supply conductor to transmitan impulse to one of said prepared operating circuits to operate an alternative one of said next higher and next lower count relays and thereby-effect alternatively addition and subtraction of a single digit from said preset number.

9. A counting chain comprising: a units bank including a plurality of counting chain blocks, each of said blocks comprising input means, a count relay operative responsive to receipt of an impulse over said input means, an associated sequence relay connected for operation responsive to operation of its respective count relay, arst contact set operable by each of said sequence relays to prepare an operating circuit for the next higher count relay responsive to operation of a given one of said sequence relays, and a second contact set operable by each of said sequence relays to prepare an operating circuit for the next lower count relay responsive to operation of said given sequence relay; and a tens bank comprised of a like number of counting chain blocks connected in like manner, and further including means for transmitting an additive impulse to the tens bank responsive to registration of each tenth additive impulse on the units bank, and for transmitting a subtractive impulse to the tens bank responsive to registration of each tenth subtractive impulse on the units bank.

lil. A counting chain comprising: a units bank including a plurality oi counting chain blocks, each of said blocks comprising input means, a count relay operative responsive to receipt of an impulse over said ini. ut means, an associated sequence relay connected for operation responsive to operation of its respective count relay, a iii-st contact set operable by each of said sequence relays to prepare an operating circuit for the next higher count relay responsive to operation of a given one ot said sequence relays and a second contact set operable by each of said sequence relays to prepare an operating circuit tor the next lower count relay responsive to operation of said given sequence relay; and a tens banlr comprised of -a like number of counting chain blocks connected in like awww manner, and furher incudng a ens forward relay '-J-.f'ich is prepared for operain responsive to Gpermien of 'le last sequence relay n 111e units bank and W1 'i is fuereafer opex'ated responsive to operacnn of the rs count reay in said units bank, and a. rens reverie elay which is prepaed for operaon responsive to operation of he rs sequence reay in said units bank and which is there a'er operated responsive to operation of the last canut reay in said units bank.

Re'eremees Sie in the le of this paent UNITED STATES PATENTS Hershey Iuly 23, 1935 Sewart Mar. 25, 1941 Kinkllead 1 Mar. 25, 1947 John Oct. 23, 1955 FOREIGN ATENTS Great Britain May 21, 1947 

6. A COUNTING CHAIN COMPRISING: A PLURALITY OF COUNTING CHAIN BLOCKS, EACH OF SAID BLOCKS COMPRISING INPUT MEANS, A COUNT RELAY OPERATIVE RESPONSIVE TO RECEIPT OF AN IMPULSE OVER SAID INPUT MEANS, AND AN ASSOCIATED SEQUENCE RELAY CONNECTED FOR OPERATION RESPONSIVE TO OPERATION OF ITS RESPECTIVE COUNT RELAY; A FIRST CONTACT SET OPERABLE BY EACH OF SAID SEQUENCE RELAYS TO PREPARE AN OPERATING CIRCUIT FOR THE NEXT HIGHER COUNT RELAY RESPONSIVE TO OPERATION OF A GIVEN ONE OF SAID SEQUENCE RELAYS; A SECOND CONTACT SET OPERABLE BY EACH OF SAID SEQUENCE RELAYS TO PREPARE AN OPERATING CIRCUIT FOR THE NEXT LOWER COUNT RELAY RESPON- 